You have created overlays in .png format, for your systems or games, with a transparency zone and you want to generate the configuration files? ARRM can do it for you.
Video Tutorial
Here are the steps to follow :
If your overlays are system overlays they must be named the same as your systems (example: 3do.png).
If your overlays are game overlays you will have to name them the same way as the rom file (example: Ace of Aces (USA).png)
then click on the System Overlay button of the Systems panel